From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 437CDC433ED for ; Mon, 26 Apr 2021 18:08:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A45F613BF for ; Mon, 26 Apr 2021 18:08:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234608AbhDZSJd (ORCPT ); Mon, 26 Apr 2021 14:09:33 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:37098 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234690AbhDZSJL (ORCPT ); Mon, 26 Apr 2021 14:09:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619460509; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=A1r1y2XmXpPoWoQQIZR44ApqAwQCbrMIhs03n4zkI9M=; b=PjgoSaV4PITRiz4sQcggQ6pic0/dANfMcTHYyfF+FfWXqMYB5cVNm17jYUCwfsZf1dqBSr 9peOSTu5VCYlECpMwq89hniDLjgiuwZNyr4H778QzpXPIPs5T+KtfxbP6cxfZue1lxSP78 wAIQgr9Ycqff1a+xppImjo1yeJiOelE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-557-s-SJ1R8rOjSd00roqxDARw-1; Mon, 26 Apr 2021 14:08:26 -0400 X-MC-Unique: s-SJ1R8rOjSd00roqxDARw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 593816D4FA; Mon, 26 Apr 2021 18:08:24 +0000 (UTC) Received: from horse.redhat.com (ovpn-114-66.rdu2.redhat.com [10.10.114.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9642F19C78; Mon, 26 Apr 2021 18:08:17 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 251CE220BCF; Mon, 26 Apr 2021 14:08:17 -0400 (EDT) Date: Mon, 26 Apr 2021 14:08:17 -0400 From: Vivek Goyal To: Matthew Wilcox Cc: linux-fsdevel@vger.kernel.org, linux-nvdimm@lists.01.org, dan.j.williams@intel.com, linux-kernel@vger.kernel.org, virtio-fs@redhat.com, miklos@szeredi.hu, jack@suse.cz, slp@redhat.com, groug@kaod.org Subject: Re: [PATCH v4 1/3] dax: Add an enum for specifying dax wakup mode Message-ID: <20210426180817.GF1741690@redhat.com> References: <20210423130723.1673919-1-vgoyal@redhat.com> <20210423130723.1673919-2-vgoyal@redhat.com> <20210426134632.GM235567@casper.infradead.org> <20210426175217.GD1741690@redhat.com> <20210426180211.GP235567@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210426180211.GP235567@casper.infradead.org> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 26, 2021 at 07:02:11PM +0100, Matthew Wilcox wrote: > On Mon, Apr 26, 2021 at 01:52:17PM -0400, Vivek Goyal wrote: > > On Mon, Apr 26, 2021 at 02:46:32PM +0100, Matthew Wilcox wrote: > > > On Fri, Apr 23, 2021 at 09:07:21AM -0400, Vivek Goyal wrote: > > > > +enum dax_wake_mode { > > > > + WAKE_NEXT, > > > > + WAKE_ALL, > > > > +}; > > > > > > Why define them in this order when ... > > > > > > > @@ -196,7 +207,7 @@ static void dax_wake_entry(struct xa_state *xas, void *entry, bool wake_all) > > > > * must be in the waitqueue and the following check will see them. > > > > */ > > > > if (waitqueue_active(wq)) > > > > - __wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key); > > > > + __wake_up(wq, TASK_NORMAL, mode == WAKE_ALL ? 0 : 1, &key); > > > > > > ... they're used like this? This is almost as bad as > > > > > > enum bool { > > > true, > > > false, > > > }; > > > > Hi Matthew, > > > > So you prefer that I should switch order of WAKE_NEXT and WAKE_ALL? > > > > enum dax_wake_mode { > > WAKE_ALL, > > WAKE_NEXT, > > }; > > That, yes. > > > And then do following to wake task. > > > > if (waitqueue_active(wq)) > > __wake_up(wq, TASK_NORMAL, mode, &key); > > No, the third argument to __wake_up() is a count, not an enum. It just so > happens that '0' means 'all' and we only ever wake up 1 and not, say, 5. > So the logical way to define the enum is ALL, NEXT which _just happens > to match_ the usage of __wake_up(). Ok, In that case, I will retain existing code. __wake_up(wq, TASK_NORMAL, mode == WAKE_ALL ? 0 : 1, &key); Vivek